JP2008088691A - Tunnel lining form and tunnel lining construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a volume of concrete placed in a space in which a concrete placed state cannot be visually confirmed, and to facilitate visual confirmation in a region in which the concrete placed state can be visually confirmed, in tunnel lining construction. <P>SOLUTION: A blow-up port 40 for supplying concrete 9 at high pressure is provided in an arch 13 being a part positioned below a ceiling 10 and adjacent to the ceiling 10 in a form 1A for tunnel lining. Pressure in the blow-up port 40 is sufficient for feeding the concrete 9 to be discharged from the blow-up port 40 above the form against gravity. A window 5c allowing the worker to observe the concrete 9 placed state is provided at the ceiling 10. Concrete is placed as horizontally as possible up to a position in which the concrete placing can be visually confirmed through the window 5c by using the form 1A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tunnel lining construction technique.

  In tunnel lining work in which the excavation surface (inner wall surface) of a moat tunnel made by excavating a natural ground is covered with concrete, first, primary lining is often performed by spraying concrete onto the excavation surface of the moat tunnel. After that, a secondary lining is performed in which the tunnel excavation surface after the primary lining is further covered with concrete.

  In the secondary lining, concrete is placed using a so-called centle formwork. In this specification, “placement” means filling concrete that has not been cured and hardened between the mold and the inner wall surface of the tunnel.

  As can be seen from FIGS. 6 and 7, the formwork 1 used in the secondary lining is, for example, a so-called “kamaboko shape” having an arc cross section, and a tunnel (hereinafter simply referred to as a tunnel) 3 after the primary lining is completed. It is installed at a predetermined position in the longitudinal direction.

  The mold 1 is provided with a large number of windows 5 that can be opened and closed on the entire wall surface. In addition, in order to distribute the concrete transport pipe 7 for placing concrete for secondary lining and the placed concrete 9 uniformly between the mold 1 and the inner wall surface 3a of the tunnel, inside the mold 1 Is equipped with a vibrator 8 for compaction. In addition, what is shown with the code | symbol 20 is the mount frame provided in the formwork 1. FIG.

  Then, the concrete conveying pipe 7 is thrown into the formwork from the window 5 (see FIG. 8), and the concrete 9 is poured from the concrete conveying pipe 7 so as to cover the tunnel 3 having a predetermined thickness. Do.

  The concrete 9 discharged from the concrete transfer pipe 7 flows downward due to gravity (see the arrow in FIG. 7), and is gradually filled upward from the lower part of the tunnel 3. As the filling amount increases, the concrete conveying pipe 7 that has been put into the mold from the lower window portion 5 can no longer be put into the window portion 5. In that case, the window part 5 used so far is closed, and this time, the concrete conveying pipe 7 is taken out from the window part 5 different from the window part 5 (usually located above), and similarly the concrete 9 Is discharged and further placement is performed.

  Further, the operator observes the placement state from the window portion 5 and checks the presence or absence of a portion where the concrete 9 is not spread, and proceeds with the operation while confirming that there is no filling leakage.

  Further, the vibrator 8 is inserted from the window portion 5 and compacted so that the concrete 9 is sufficiently distributed between the mold 1 and the tunnel inner wall surface 3a as described above.

  On the other hand, the uppermost part of the formwork 1 is referred to as a ceiling part and is denoted by reference numeral 10. The space 9 (hereinafter referred to as the top end portion) 15 between the ceiling portion 10 and the tunnel 3 is also filled with the concrete 9 like the arch portion 13 below.

As shown in FIG. 8, the concrete placement of the ceiling part 10 is provided with a blowing outlet 11 at the intersection point i between the median line C in the cross section of the tunnel 3 and the inner surface of the mold 1 in the ceiling part 10. The concrete 9 is discharged from the mold outside the mold. For the sake of convenience, in this specification, the ceiling portion 10 refers to an arc in the mold 1 that is defined by the tangent T intersecting the outer peripheral surface of the mold 1 when the tangent T is drawn at the intersection i. The part which has a part in a cross section shall be said.

  Further, the ceiling portion 10 is provided with an openable and closable window portion similar to the window portion 5, which is referred to as a ceiling window and denoted by reference numeral 5 c. The ceiling window 5 c is located at the top of the ceiling portion 10. The midline C is a line passing through the top of the mold 1 because it is located at the center of the cross section of the mold 1.

  From the ceiling window 5 c and the other window parts 5, the operator can confirm the placement state of the concrete 9 up to the arch part 13 positioned below the ceiling part 10. On the other hand, when placing on the ceiling portion 10, the placement state cannot be visually recognized after the window portion 5 is closed.

  Nevertheless, finally, the top end portion 15 must be filled by ejecting concrete from the blowing port 11 at the upper part of the formwork. In the conventional method, the top end portion 15 that needs to be constructed in such a state is larger, and the larger the top end portion 15 is, the more difficult it is to ensure the concrete filling property. In addition, the range shown by the symbol A shown in FIG. 8 is an area (space) in which filling is impossible only with the concrete discharged from the concrete conveying pipe 7 that has come out from the window portion 5 of the arch portion 13. 11 is a range that requires concrete filling from 11. The presence of the range A is also a factor that enlarges the top end 15.

  Further, since the gradient becomes gentler toward the upper side at the mold side, it can only be placed up to a position where the poured concrete flows down. Accordingly, there is a problem that it takes time to drive the upper portion of the arch portion due to such a cause.

Furthermore, in the filling operation by the concrete conveying pipe 7 of the window portion 5, since concrete is poured into the mold by natural fall, it is difficult to place it horizontally and it is difficult to visually check the placement state.
JP 2003-227297 A

  The present invention has been made in view of the above circumstances, and the problem to be solved is that the concrete placement amount in a space where the placement state cannot be visually recognized (such as the top end portion) can be reduced in the tunnel lining construction. On the other hand, it is to provide a technique for facilitating visual recognition in an area where the placement state can be visually recognized.

  The tunnel lining formwork of the present invention is a tunnel lining formwork, wherein the arch part is located below the ceiling part of the formwork and adjacent to the ceiling part. A blow-up port for pressing and discharging the concrete is provided, and the ceiling portion is provided with a window portion for observing the placement state of the concrete, and in the vicinity of the window portion, the uppermost position of the mold The uppermost blowing outlet located in is provided.

  Since the concrete discharged by pressurization from the air outlet provided in the arch portion can be placed toward the upper side of the mold against gravity, the concrete supplied from the air outlet Can be supplied to the vicinity of the top of the ceiling in a short time.

Accordingly, it is possible to reduce the volume of the top end portion where the concrete is filled by the uppermost blowing outlet thereafter.

  The uppermost blowing outlet and the blowing outlet of the arch part discharge the concrete with a sufficiently high discharge pressure, and a plurality of blowing openings provided in the arch part are arranged so as to surround the ceiling part. Is desirable.

  In this case, it is possible to place the concrete horizontally up to the vicinity of the top of the ceiling by switching the blast of the arch part. The installation state can be easily confirmed from the window of the ceiling.

  As a result, the concrete around the ceiling placed by discharging from the air outlet of the arch can be made to reach the operator's eyes sufficiently from the window of the ceiling. For example, it is possible to suppress the occurrence of a gap due to the fact that the concrete does not spread between the wall and the inner wall surface of the tunnel.

  The tunnel lining construction using the above-mentioned formwork is made by pressing concrete from the air outlet provided in the arch part and ejecting it between the formwork and the tunnel below and above this air outlet. The method includes filling concrete and placing the concrete up to the vicinity of the top of the ceiling so that the placing surface is horizontal.

  When discharging concrete from the plurality of air outlets, the concrete is discharged while adjusting the discharge amount and time of the concrete discharged from the air outlets so that the concrete is supplied substantially uniformly around the ceiling. You may make it have the process to do.

  It is also possible to carry out a step of ejecting concrete from the uppermost air outlet after the position of placing by the concrete reaches the uppermost vicinity of the ceiling portion.

  When the concrete placement position reaches near the topmost position of the ceiling portion, a step of applying vibration to the placement portion with a vibrator may be included.

  According to the tunnel lining construction method of the present invention, since the concrete can be placed above the air outlet of the arch portion, the top end portion 15 can be made small. Therefore, it is possible to reduce the amount and time of placing concrete by the uppermost blowing outlet.

  Moreover, since it becomes easy to place concrete concrete horizontally, the range which an operator can visually recognize the placement state from the window part of a ceiling part can be expanded. As a result, it is possible to effectively suppress the generation of a gap due to the fact that concrete does not spread between the formwork and the inner wall surface of the tunnel.

  Furthermore, since the placement is completed in a short time, the quality of the concrete is improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a tunnel lining form and a tunnel lining construction method of the present invention (hereinafter referred to as embodiments) will be described with reference to the accompanying drawings.

  In addition, the same code | symbol is attached | subjected to the part same as a prior art, and description is abbreviate | omitted.

As shown in FIGS. 1 to 5, the tunnel lining mold 1 </ b> A is different from the conventional mold 1 as follows.
(A) A plurality of blast ports 40 for blowing concrete 9 at high pressure are provided in the arch portion 13 which is located below the ceiling portion 10 of the mold 1A and adjacent to the ceiling portion 10 ( (See FIGS. 4 and 5).
(B) The high pressure of the blow-up port 40 is to have sufficient pressure to direct the concrete 9 discharged from the blow-up port 40 upward of the mold 1A against gravity (in FIG. 4, upward from the blow-up port 40). See arrow a).

  Therefore, these differences and the parts related to them will be described in detail below.

  As shown in FIG. 5, a total of four blowing openings 40 are arranged on the left and right sides of the ceiling portion 10, and as a result, surround the ceiling portion 10 of the mold 1 </ b> A.

  When discharging the concrete 9 from the four air outlets 40, the concrete 9 is discharged while adjusting the amount of the discharged concrete 9 so that the concrete 9 is almost uniformly filled around the ceiling portion 10. For example, when the filling efficiency of the concrete 9 related to the air outlet 40 located in the upper left of FIG. 5 is poor and less than the concrete 9 accumulated in the placement area related to the other air outlet 40, the air outlet located in the upper left The discharge amount of the concrete 9 from 40 is increased more than that of the other blowing openings 40, or the discharge time is lengthened. That is, the filling degree is increased by press-fitting the concrete 9, and the concrete 9 is placed so that the placement surface is as horizontal as possible regardless of the placement related to any air outlet 40.

  In addition, the casting speed of the concrete 9 is slow above the mold 1 where the gradient becomes gentle, and the conventional method has a problem that the filling density is lowered. However, in the method of the present invention, the blowing port 40 is provided with the concrete 9. Is pressurized and ejected, so that it can be placed both below and above the blow-up port 40, and the packing density increases on either side.

  In this case, since the placing in a short time is possible, the trouble that the concrete 9 hardens is suppressed. That is, the filling degree of the concrete 9 can be drastically increased by completing the placement without solidifying the concrete 9.

  Note that the blowing outlet 11 located at the top of the ceiling 10 is referred to as the highest blowing outlet 11 in comparison with the blowing outlet 40 in the arch part 13. The uppermost blow-up port 11 is used to fill the concrete 9 in the top end 15 which is a space between the ceiling 10 and the tunnel inner wall surface 3a after the filling by the blow-up port 40 is completed. Concrete 9 is discharged with a suitable discharge pressure. Further, as a reserve for the uppermost blow-up port 11, a preliminary blow-up port 11a is provided in the ceiling portion 10 in the longitudinal direction (see FIG. 5).

  Further, in the mold 1A, in addition to the vibrator 8, for example, a drawing vibrator 80 disclosed in Japanese Patent Laid-Open No. 2003-227297 is used (see FIGS. 3 and 4).

  Next, a tunnel lining construction method using the tunnel lining mold 1A having such a configuration will be described.

The tunnel lining construction method according to this embodiment includes the following steps (i) to (v).
(I) The concrete 9 supplied from the air outlet 40 provided in the arch part 13 is driven to a place (refer to the upper surface of the concrete 9 in FIG. 4) that is substantially horizontal with the uppermost part of the ceiling part 10. Step.
(Ii) The ceiling window 5c of the ceiling portion 10 indicates that the position of placement by the concrete 9 supplied from the air outlet 40 provided in the arch portion 13 reaches a location that is substantially horizontal with the top of the ceiling portion 10. Steps observed by the worker.
(Iii) When the placement position of the concrete 9 is almost horizontal with the top of the ceiling 10,
Discharging the concrete 9 from the uppermost blowing port 11;
(Iv) When discharging the concrete 9 from the plurality of blowing openings 40 provided in the arch portion 13, the concrete discharged from the blowing openings 40 so that the concrete 9 is supplied substantially uniformly around the ceiling portion 10. A step of discharging while adjusting the discharge amount and discharge time of No. 9.
(V) A step of applying vibrations to the placement portion with vibrators 8 and 80 when the placement position of the concrete 9 is substantially horizontal with the top of the ceiling portion 10.

  Next, the effect of this embodiment is described.

  Since the concrete 9 discharged from the plurality of air outlets 40 provided in the arch portion 13 can be placed toward the ceiling portion 10 above the formwork 1A against gravity, The concrete 9 supplied from the mouth 40 can be placed up to a place that is substantially horizontal with the top of the ceiling 10.

  As described above, by placing horizontally, the range in which the operator can visually recognize the placement state from the ceiling window 5c can be expanded.

  Conventionally, the concrete conveying pipe 7 is taken out from the window 5 provided in the arch portion 13 and the concrete 9 is discharged from the concrete conveying pipe 7 to fill the concrete. However, instead of the concrete conveying pipe 7, the concrete 9 By using the blow-up port 40 having sufficient pressure to direct the upper side of the mold 1A, the concrete 9 can be filled into the space A (see FIGS. 8 and 5), which has not been achieved so far. Thus, the volume of the top end 15 can be reduced accordingly. Therefore, the filling property of the concrete 9 at the top end portion 15 can be ensured. In particular, it is possible to effectively suppress the generation of a gap due to the fact that the concrete 9 is not spread between the mold 1A and the tunnel inner wall surface 3a.

  Further, when an operator overlooks the ceiling portion 10 from the ceiling window 5c, the concrete 9 discharged from the four blow-up openings 40 is filled (placed) to a place that is substantially horizontal with the topmost portion of the ceiling portion 10. ) Can be confirmed (see FIG. 4). In this case, it becomes a situation that the concrete 9 may be filled using the uppermost blow-up port 11 with respect to the top end portion 15 that remains slightly.

  As described above, since the concrete 9 can be placed not only below but also above the blow-up opening 40, the possible placement range by this method is widened. As a result, the ceiling is a space where the worker cannot visually recognize the placement state. The amount of concrete placed on the portion 15 can be reduced. It is important to minimize the amount and time of placing the top end 15 where the placement state cannot be visually recognized. However, by realizing this, the concrete 9 can be placed on the top end 15. Fillability can be improved.

  In addition, this invention is not limited only to the above-mentioned illustration example, Of course, various changes can be added within the range which does not deviate from the summary of this invention. For example, the shape of the steel pipe may be a square steel pipe. In this case, of course, the ring plate is also rectangular.

It is a cross-sectional view which shows the state which is constructing the tunnel lining using the tunnel lining formwork according to the present invention. It is a side view which shows the state which is constructing tunnel lining using the tunnel lining formwork which concerns on this invention. It is a perspective view which shows the state which is performing construction of tunnel lining using the formwork for tunnel lining concerning this invention. It is a principal part enlarged view of FIG. It is a top view of the formwork for tunnel lining which concerns on this invention. It is a figure for demonstrating a prior art, Comprising: It is a cross-sectional view equivalent to FIG. It is a figure for demonstrating a prior art, and is a side view equivalent to FIG. It is a principal part enlarged view of FIG.

Explanation of symbols

1 Formwork 1A Formwork 3 Tunnel 3a Tunnel excavation surface (inner wall surface)
DESCRIPTION OF SYMBOLS 5 Window part 5c Ceiling window 7 Concrete conveyance pipe 8 Vibrator 9 Concrete 10 Ceiling part 11 Uppermost blowing outlet 11a Preliminary blowing opening 13 Arch part 20 Scaffolding 40 Lifting opening 80 Pulling vibrator C Midline T Tangent i Intersection a From blowing opening Line showing concrete facing upward

Claims (5)

In the formwork for tunnel lining,
The arch portion, which is located below the ceiling portion of the mold and adjacent to the ceiling portion, is provided with a blow-up port that pressurizes and ejects concrete.
The ceiling part is provided with a window part for observing the placement state of the concrete, and an uppermost air outlet located at the uppermost part of the mold is provided in the vicinity of the window part. Formwork for tunnel lining characterized by   2. The tunnel lining form according to claim 1, wherein a plurality of the air outlets are arranged so as to surround the ceiling portion. A tunnel lining construction method using the mold according to claim 2,
The concrete is pressurized and ejected from the air outlet provided in the arch, the concrete is filled between the formwork and the tunnel below and above the air outlet, and the ceiling is placed so that the casting surface is horizontal. Tunnel lining method including the process of placing concrete up to the top of the section.   4. The tunnel lining according to claim 3, wherein a step of ejecting the concrete from the uppermost outlet is performed after the position of placement by the concrete reaches the uppermost vicinity of the ceiling portion. 5. Construction method.   5. The tunnel lining construction method according to claim 4, wherein when the concrete placement position reaches near the uppermost position of the ceiling portion, vibration is applied to the placement portion with a vibrator.

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